LaTeX: Difference Between \frac and \dfrac?

[FilupSmith]

Hi, I'm trying to learn LaTeX and one of the things I'm trying to figure out is what is the difference between \frac and \dfrac?

I mean, look:
\frac{a}{b} is: $$\frac{a}{b}$$
\dfrac{a}{b} is: $$\dfrac{a}{b}$$

Other then the thickened line, is there really any difference?
Thank you...

 

[Char. Limit]

Looking it up, a slight display difference is the only real change that you'll see on PF.

 

[strangerep]

Since the "d" is short for "\displaystyle" or "\D", you'll only see a difference for inline latex, e.g., $\frac{a}{b}$ versus $\dfrac{a}{b}$

 

[FilupSmith]

I looked it up and i believe the only difference is that \tfrac or \frac allow for text sized fractions (great for 1/3, etc.) while \dfrac is best for formulas! Thanks none the less!

 

[AlephZero]

\frac automatically scales to the "best" size depending on the position in the formula, as well as changing between inline and display math. \dfrac and \tfrac don't change size.

Use \frac, unless you don't want the default size.

 ##\frac{1}{2} 3^{\frac{1}{2}}\quad 
\dfrac{1}{2}3^{\dfrac{1}{2}}\quad 
\tfrac{1}{2}3^{\tfrac{1}{2}}##

$$\frac{1}{2} 3^{\frac{1}{2}}\quad 
\dfrac{1}{2}3^{\dfrac{1}{2}}\quad 
\tfrac{1}{2}3^{\tfrac{1}{2}}$$

$\frac{1}{2} 3^{\frac{1}{2}}\quad \dfrac{1}{2}3^{\dfrac{1}{2}}\quad \tfrac{1}{2}3^{\tfrac{1}{2}}$

$$\frac{1}{2} 3^{\frac{1}{2}}\quad
\dfrac{1}{2}3^{\dfrac{1}{2}}\quad
\tfrac{1}{2}3^{\tfrac{1}{2}}$$